1. Field of the Invention
This invention relates to a still image sensing apparatus in which the white balance is controlled by the video signal output from an image sensor.
2. Description of the Related Art
In the white balance control of the still image sensing apparatus, it has been the typical practice that, besides the image sensor, there is provided a colorimetric sensor for detecting the color temperature information of the light source. Based on the output of this senor, the video signals output from the image sensor are controlled so as to obtain good white balance.
However, the above-described conventional method not only necessitates the use of the colorimetric sensor, but also cannot make accurate white balance control when the color temperature of the light source at which the colorimetric sensor aims differs from that of a virtual light source which is illuminating an object being photographed.
Another problem of the prior known method is that the so-called release time lag gets longer, because the time space necessary to detect the color temperature information and then make preparation for the white balance control up to its completion must fall within the interval from the depression of the shutter button to the initiation of an actual exposure. In this case, it often happens that the real color temperature information differs from the measured one at the time of colorimetry.